无锡市区土体工程地质层组划分及其应用

Division and application of engineering geological strata groups of soil mass in Wuxi City

无锡市区地处太湖冲湖积平原区,第四纪松散沉积物较厚,城市建设多以土体为载体,土体结构质量关系到工程建设的成本和周期,但长期以来无锡市区土体工程地质层组划分并无统一标准,地层代号编码混乱,严重降低了工程地质资料的可重复利用率。为提高无锡市区工程地质资料的通用性,使其利用价值最大化,文章基于大量地质钻孔和土体参数测试数据,对比区域地层资料,综合考虑研究区沉积演化特征、土体物质组成及工程特性等因素,采用绘制工程地质剖面的方法建立地层层序结构和编码规则,将无锡市区100 m以浅的土体划分为9个工程地质层组和27个工程地质亚层。利用土体参数的离散性和三维地质结构模型分析了该工程地质层组划分方案的合理性,并探讨了该划分结果在优势持力层的选择、地下空间开发利用适宜性评价和浅层地热能开发利用中的应用。结果显示,该土体工程地质层组划分方案能准确地反映无锡市区100 m以浅的土体结构,划分方案合理正确。

Wuxi City is located in the alluvial and lacustrine plain of the Taihu Lake,with thick quaternary loose sediments,where urban construction mostly takes soil as the carrier,and the quality of soil structure is related to the cost and cycle of engineering construction.However,for a long time,there has been no unified standard for the division of soil mass engineering geological strata in Wuxi city,and the stratum coding is confused,which seriously reduces the reusability of engineering geological data.In order to improve the universality of engineering geological data and maximize its utilization value,based on a large amount of geological drilling and soil parameter testing data etc.,this article establishes stratigraphic sequence structure and coding rules through drawing engineering geological sections.The soil mass within a depth of 100 m in Wuxi is divided into 9 engineering geological strata groups and 27 engineering geological layers.The rationality and correctness of this engineering geological strata group division scheme has been proved through the discrete characteristics of soil parameters and the 3D geological structure model.The result is widely used in the selection of pile foundation bearing layer,evaluation of suitability for underground space development and utilization,and shallow geothermal energy development.The result also has guiding significance for engineering investigation,urban planning,construction and management,and major project site selection in Wuxi City.